To Which One of the Following Reactions Occurring at 25°C $\Delta$

To which one of the following reactions occurring at 25°C does the symbol $\Delta$ H°_f[HNO₃(l) ] refer?

A) H(g) + N(g) + O₃(g) $\rarr$ HNO₃(l)
B) (1/2) H₂(g) + (1/2) N₂(g) + (3/2) O₂(g) $\rarr$ HNO₃(l)
C) HNO₃(l) $\rarr$ (1/2) H₂(g) + (1/2) N₂(g) + (3/2) O₂(g)
D) HNO₃(l) $\rarr$ H(g) + N(g) + 3O(g)
E) H₂(g) + N₂(g) + O₃(g) $\rarr$ HNO₃(l)